Web Services Development Kit WSDK

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Web Services Development Kit (WSDK)

• John Bristowe Senior Solution Developer
• Empowered Software Solutions

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WSDK

• Technical preview available from MSDN since
  August 26th, 2002
• .NET class library (Microsoft.WSDK.dll) for
  building Web services that utilize the latest Web
  service protocols
• Support for various GXA specifications
• WSDK exposes two programming models Low-level
  API for direct access, higher-level integration
  with ASP.NET, exposed through ASMX

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GXA Support

• WSDK currently supports WS-Security, WS-Routing,
  WS-Referral, DIME, and WS-Attachments
• WSDK currently does not support WS-Inspection,
  WS-Coordination, or WS-Transaction

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WSDK Process Model
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WSDK Process Model

• SOAP messages are processed as they cross
  application boundaries utilizing a pipeline of
  filters
• Filters are responsible for processing SOAP
  headers

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Filters

• Headers are written to outbound SOAP messages
• Headers are read from inbound SOAP messages
• Certain GXA specifications mandate transforming
  the SOAP message body (i.e. WS-Security)
• Filters may be used with other filters to form
  filter chains
• WSDK supports custom filters

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SoapContext

• Access to SOAP headers is provided by the
  SoapContext class
• On the client, SoapContext is exposed via
  RequestSoapContext and ResponseSoapContext
  through WSDKClientProtocol
• On the server, SoapContext is exposed via
  RequestContext and ResponseContext through
  HttpSoapContext module

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SoapContext
SoapContext
Attachments
Referrals
Security
Path
Timestamp
Envelope
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Client Side

• SoapWebRequest
• SoapWebResponse

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Server Side

• WSDK functionality is exposed through
  Microsoft.WSDK.HttpModule, an ASP.NET HTTP module
• Responsible for establishing input and output
  filter chains when a SOAP message is received

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Processing a Request

• Checks to see if the SOAP message targets a
  Remoting endpoint (i.e. .rem, .soap)
• Verifies that a SOAPAction exists
• Initializes RequestSoapContext and
  ResponseSoapContext
• Initializes configuration
• Establishes input and output filter chains to
  request/response

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Filtering SOAP Messages

• Pipeline is responsible for driving the SOAP
  envelope through the filter chain
• WSDK pipeline mimics IBMs WSTK
• Output filters (possibly) modify the contents of
  the message body (i.e. encryption) based on
  context
• Input filters check the validity of headers and
  (possibly) modify the contents of the message
  body (i.e. decryption) based on context

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Input Filters

• TraceInputFilter
• RoutingInputFilter
• ReferralInputFilter
• SecurityInputFilter
• TimestampInputFilter

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Output Filters

• TraceInputFilter
• RoutingInputFilter
• ReferralInputFilter
• SecurityInputFilter
• TimestampInputFilter

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WSDK Configuration

• Utilizes Web.config
• WSDK defines an additional configuration section
  microsoft.wsdk
• Facilitates the use of custom filters
• Specifies various diagnostic capabilities
• Defines routing information
• Controls security settings (i.e. X509 store
  location)

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Configuration Sample

• ltconfigurationgt
• ltmicrosoft.wsdkgt
• ltdiagnosticsgt
• lttracing enabledtrue inputinput.xml
  outputoutput.xml /gt
• lt/diagnosticsgt
• ltreferralgt
• ltcache namereferralCache.config /gt
• lt/referralgt
• ltsecuritygt
• ltx509 storeLocationLocalMachine
  verifyTrusttrue allowTestRootFalse /gt
• lt/securitygt
• lt/microsoft.wsdkgt
• lt/configurationgt

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Machine.config

• WSDK installation modifies machine.config to add
  ConfigHandler for microsoft.wsdk section
• Machine-wide configuration is well documented in
  WSDK.config located in the installation directory
  of the WSDK

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ASP.NET WebMethods

• Transparent integration via HttpModule

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Creating Clients

• Two options roll by hand or use the Web Services
  Description Language tool (wsdl.exe)

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WS-Security

• Supported through Microsoft.WSDK.Security.
• Contains types that enable handling SOAP messages
  encrypted, signed, and secured with X.509
  certificates, user name tokens, and custom binary
  security tokens

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WS-Timestamp

• Supported through Microsoft.WSDK.Timestamp
• Contains types that enable setting the
  expiration, creation, and received times of
  messages
• Useful in a security scenario

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WS-Attachments/DIME

• Supported through Microsoft.WSDK.Dime
• Contains types that enable to send and receive
  binary data attached to SOAP messages
• Stream reader (DimeReader) and writer
  (DimeWriter)
• Support for chunked records (DimeRecord)

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WS-Routing

• Supported through Microsoft.WSDK.Routing
• Contains types that enable the transparent
  routing of calls to a WSDK application
• Provides programmatic access to Path elements
  (i.e. Action, To, From, Fwd, Rev, etc.)

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WS-Referral

• Supported through Microsoft.WSDK.Referral.
• Contains types that enable the redirection of
  calls to a WSDK application

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Referral Cache

• Inspected by the RoutingHandler for each incoming
  SOAP message
• Routing instructions in a configuration file
  (i.e. referralCache.config), which prevents
  ASP.NET from being serving it up through HTTP

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Updating the Referral Cache

• Upon servicing a request, a handle to
  referralCache.config is created
• ASP.NET worker process retains this handle,
  effectively locking the file
• Touching web.config will unload it from memory
  and release the handle (non-optimal)
• Update referralCache.config by creating a new
  file and update web.config to have it referenced
  (recommended)

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Interoperability

• Implementation of WS-Security in WSDK is
  compatible with IBMs Web Services Toolkit (WSTK)
  v3.2.2
• BEA WebLogic Workshop?

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Troubleshooting

• Diagnostics
• Tracing
• Application event log
• ASP.NET worker process
• Set DACLs accordingly
• X509 Certificates
• Database permissions
• Trust chains

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WSDK

• Pros
• Easy to program
• Extensible
• Configurable
• Cons
• Troubleshooting
• Lack of support for other remoting stacks

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Articles Resources

• Test-Drive Microsofts New Web Services
  Development Kit by Roger Jennings, XML Web
  Services Magazine
• Programming with the Web Services Development
  Kit Technology Preview by Tim Ewald, MSDN
• Using WS-Security with the Web Services
  Development Kit Technology Preview by Matt
  Powell, MSDN

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Blogs

• Don Box
• Tim Ewald
• Keith Ballinger
• Ingo Rammer
• Clemens Vasters
• Werner Vogels
• Jon Udell
• John Burkhardt

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Communities

• Microsoft newsgroups
• microsoft.public.webservices
• microsoft.public.webservices.wsdk
• DevelopMentor Lists
• http//discuss.develop.com/
• ASP.NET Forums
• http//www.asp.net/forums/

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URLs

• MSDN XML Web Services Developer Center
• http//msdn.microsoft.com/webservices/
• OakLeaf Systems
• http//www.oakleaf.ws/
• Casey Chesnut
• http//www.brains-n-brawn.com/

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Contact Information

• john.bristowe_at_empowered.com